tools: wc, head, and an argc/argv demo (args) + libc.c helpers

- c/libc.c: shared C helpers linked into every program - putu (print decimal),
  atou (parse decimal), argv_parse (tokenize getargs() into argc/argv).
- wc: count lines/words/chars of stdin. head [n]: first n lines (drains rest to
  EOF). args: argc/argv demo.
- pid now uses libc putu; build.sh links libc.c; Makefile CBLOBS + libc dep.
- README: document the new tools + argv_parse.
- verified: 'args one two three' -> argc=3/argv[..]; wc '2 3 16'; head 2.

1 files changed, 21 insertions, 0 deletions

diff --git a/src/programs.asm b/src/programs.asm
index 322c7fc..a3a6db2 100644
--- a/src/programs.asm
+++ b/src/programs.asm
@@ -70,6 +70,15 @@ ProgPid:
 SECTION "prog_cat",    ROMX[$4000], BANK[11]
 ProgCat:
     INCBIN "c/cat.bin"
+SECTION "prog_wc",     ROMX[$4000], BANK[12]
+ProgWc:
+    INCBIN "c/wc.bin"
+SECTION "prog_head",   ROMX[$4000], BANK[13]
+ProgHead:
+    INCBIN "c/head.bin"
+SECTION "prog_args",   ROMX[$4000], BANK[14]
+ProgArgs:
+    INCBIN "c/args.bin"
 
 ; -----------------------------------------------------------------------------
 ; PROG_SH (bank 3) - a tiny shell.
@@ -202,6 +211,12 @@ ProgSh:
     db PROG_PID
     db "cat", 0
     db PROG_CAT
+    db "wc", 0
+    db PROG_WC
+    db "head", 0
+    db PROG_HEAD
+    db "args", 0
+    db PROG_ARGS
     db 0                        ; terminator
 
 ; -----------------------------------------------------------------------------
@@ -256,3 +271,9 @@ ProgramTable::
     dw ProgPid
     db LOW(BANK(ProgCat)), HIGH(BANK(ProgCat))
     dw ProgCat
+    db LOW(BANK(ProgWc)), HIGH(BANK(ProgWc))
+    dw ProgWc
+    db LOW(BANK(ProgHead)), HIGH(BANK(ProgHead))
+    dw ProgHead
+    db LOW(BANK(ProgArgs)), HIGH(BANK(ProgArgs))
+    dw ProgArgs